CHOOSING A GOOD GRAPHICS CARD

A top-of-the-line graphics card is easy to spot. It has lots of memory and a fast processor. Often, it's also more visually appealing than anything else that's intended to go inside a computer's case. Lots of high-performance video cards are illustrated or have decorative fans or heat sinks.

But a high-end card provides more power than most people really need. People who use their computers primarily for e-mail, word processing or Web surfing can find all the necessary graphics support on a motherboard with integrated graphics. A mid-range card is sufficient for most casual gamers. People who need the power of a high-end card include gaming enthusiasts and people who do lots of 3-D graphic work.

Integrated Graphics

Many motherboards have integrated graphics capabilities and function without a separate graphics card. These motherboards handle 2-D images easily, so they are ideal for productivity and Internet applications. Plugging a separate graphics card into one of these motherboards overrides the onboard graphics functions. Some cards, like the ATI All-in-Wonder, include connections for televisions and video as well as a TV tuner.

A good overall measurement of a card's performance is its frame rate, measured in frames per second (FPS). The frame rate describes how many complete images the card can display per second. The human eye can process about 25 frames every second, but fast-action games require a frame rate of at least 60 FPS to provide smooth animation and scrolling. Components of the frame rate are:

• Triangles or vertices per second: 3-D images are made of triangles, or polygons. This measurement describes how quickly the GPU can calculate the whole polygon or the vertices that define it. In general, it describes how quickly the card builds a wire frame image.
• Pixel fill rate: This measurement describes how many pixels the GPU can process in a second

  The graphics card's hardware directly affects its speed. These are the hardware specifications that most affect the card's speed and the units in which they are measured:

• GPU clock speed (MHz)
• Size of the memory bus (bits)
• Amount of available memory (MB)
• Memory clock rate (MHz)
• Memory bandwidth (GB/s)
• RAMDAC speed (MHz)
• , which translates to how quickly it can rast
  Overclocking
  Some people choose to improve their graphics card's performance by manually setting their clock speed to a higher rate, known as overclockings. People usually overclock their memory, since overclocking the GPU can lead to overheating. While overclocking can lead to better performance, it also voids the manufacturer's warranty.
  erize the image. The computer's CPU and motherboard also play a part, since a very fast graphics card can't compensate for a motherboard's inability to deliver data quickly. Similarly, the card's connection to the motherboard and the speed at which it can get instructions from the CPU affect its performance.

  For more information on graphics cards and related topics, check out the links on the following page.